In the industry of timber flooring, surface planers are commonly used for surfacing each piece of raw wood, or lumbers. The lumbers are generally fed one by one in the surface planer for processing on four sides thereof. Fixed rollers are generally provided as a feed system forcing the lumbers therethrough, one after the other. Mobile heads provided with abrasion means such as knives, inside the surface planer, have different machining actions on the lumbers.
Generally, before the lumbers are fed to the surface planer, a number of operations are performed by one or several operators positioned at the input of the surface planer. For each lumber, the operators cut out major physical defects that might jam the surface planer for example. Then, for each lumber, the operators select a face thereof, which is susceptible to yield a best finish for the working surface of the floor. However, since at this stage the wood is still not at its final thickness, coloration and shades defects may not be visible and therefore a face may be wrongly selected as the potentially best one for the working face.
As illustrated in FIG. 1 of the appended drawings, the working face 12 thus selected is then surfaced, whereas the opposite face 14 is surfaced and provided with grooves 16 in a lengthwise direction to provide aeration canals once the floor is laid out. Both edges of the lumber 10 are machined, to yield a mortise 18 on a first edge and a tenon 20 on the opposite edge, along the length of the lumber. A chamfrain 22 may further be machined on each side of the working face 12.
Usually, these four machining steps, including surfacing of each face, machining the edges and providing grooves, are performed in a single machine. Therefore, the lumbers that are fed therein must be of a tightly controlled constant width and thickness to yield good results. Moreover, it is important that the lumbers be not overly wrapped along their width, in order to prevent jamming inside the machine.
Such kind of machines requires a number of adjustments to control the machining dimensions and the quality of the finished surfaces. As dimensional tolerances are very tight in the fabrication of floor, adjusting the machine is very complex and involves highly qualified operators.
As surfaced lumbers exit the machine, they are cut out and graded into planks according to color variations and physical defects. This is achieved either by operators, or by numerical vision systems or a system combining operators and numerical vision. As a result, a varying amount of material is discarded and planks downgraded, depending, as mentioned hereinbefore, on the step of working face selection.
A number of surface planers are currently available for a range of applications, including machining of hard and soft woods, of a variety of wood pieces and of planks intended for timber flooring.
Sturdy and reliable surface planers dedicated to machining of planks intended for timber flooring are currently available. Some are provided with simplified adjustment systems and steady steel frames for example. Others are less sturdy but allow knife positioning adapted to the production of planks for flooring, and high production speed.
However, these machines and their adjustment requirements are still a limit to the versatility and flexibility of the production lines.
Therefore, there is a need for a machine and a method that would overcome the above drawbacks of the prior art.